How do weather conditions affect the efficiency of photovoltaic installations?

Nowadays, solar energy has become one of the most popular and environmentally friendly energy sources. With the growing interest in photovoltaic installations, it is crucial to understand how to optimise their performance under different weather conditions. Weather and climate have a significant impact on the efficiency of solar panels, so it is useful to know strategies to maximise energy production regardless of the conditions.

How the weather affects the performance of a photovoltaic installation

1. Insolation

Insolation is the primary factor affecting the performance of photovoltaic panels. The more sunlight that reaches the panels, the more energy they can generate. However, it is worth noting that it is not only cloudless days that are beneficial for energy production. Photovoltaic panels are also able to produce energy under diffuse light, although to a lesser extent than under direct sunlight.

2 Temperature

High temperatures can cause significant energy losses. On hot days, photovoltaic panels can heat up to temperatures much higher than the ambient temperature, leading to a decrease in their efficiency. Therefore, in regions with hot climates, it is particularly important to manage the temperature of the panels to minimise energy losses. An increase in ambient temperature leads to an increase in internal resistance in the semiconductors, which in turn reduces the output voltage and overall efficiency of the panels. Temperature increases above optimum operating conditions, which are around 25°C, can reduce performance by up to 0.5% for each additional degree Celsius.

3. rain

Rain has a significant impact on photovoltaic installations, bringing both benefits and some challenges. The natural cleaning of panels, cooling and continuous, albeit reduced, energy production during rainfall are aspects worth considering when managing a photovoltaic system. Rain naturally washes away dust, dirt and other contaminants from photovoltaic panels, which improves their performance as clean panels can better absorb sunlight. Rainfall helps to cool the photovoltaic panels, which can improve their efficiency, as high temperatures reduce the energy output of the panels.

4. hail

Hail can damage the surface of photovoltaic panels, causing cracks or damage to the protective glass layer. This can lead to a reduction in efficiency or the complete immobilisation of the panels. Even minor damage can affect the panels' ability to effectively convert sunlight into electricity, reducing their overall efficiency. As a result of hail damage, there may be additional costs associated with repairing or replacing damaged panels.

5. snow

A layer of snow on photovoltaic panels can completely block sunlight, leading to a significant decrease or complete stoppage of energy production. Melting snow, on the other hand, can help clean dust and other debris from the panels, which, once melted, can improve their performance.


There are many interrelationships between PV installation and weather conditions. The efficiency of a PV installation is directly dependent on weather conditions. In the climatic zone in which Poland is located, photovoltaic panels generate the most energy in summer and much less in winter, when the sky is often overcast.

Most importantly, however, the benefits to the investor are indisputable on an annual basis. Photovoltaic panels produce energy with varying efficiency regardless of the prevailing weather conditions, operating at temperatures from -40 to +85 degrees Celsius. Any surplus energy produced in the summer is fed back into the grid and can be collected in the winter when the panels are unable to produce enough energy to meet the farm's demand.

External forces such as varying temperatures, wind, rain or snow must be taken into account when choosing panels. Therefore, the panels should have approvals and certificates confirming their superior resistance to weather conditions.

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